diff --git a/include/libc/djctx.h b/include/libc/djctx.h
index 4fcb6b50..74ed7f3f 100644
--- a/include/libc/djctx.h
+++ b/include/libc/djctx.h
@@ -26,13 +26,14 @@ void djregister_ctx_hooks(void (*)(int), void (*)(void), void (*)(void),
 
 #define SW_CTX_MAX 100
 
-#define DJ64_DEFINE_SWAPPABLE_CONTEXT2(t, c, init, pre, post) \
+#define DJ64_DEFINE_SWAPPABLE_CONTEXT3(t, c, init, pre, post, cinit) \
 static struct t t##_contexts[SW_CTX_MAX]; \
 static void t##_init(int idx) \
 { \
   struct t *x = &t##_contexts[idx]; \
   assert(c != x); \
   *x = init; \
+  cinit(x); \
 } \
 static void t##_deinit(void) \
 { \
@@ -56,6 +57,10 @@ static void static_##t##_init(void) \
   djregister_ctx_hooks(t##_init, t##_deinit, t##_save, t##_restore); \
 }
 
+#define DJ64_DEFINE_SWAPPABLE_CONTEXT2(t, c, init, pre, post) \
+  static void _dummy_cinit(struct t *dummy) {} \
+  DJ64_DEFINE_SWAPPABLE_CONTEXT3(t, c, init, pre, post, _dummy_cinit)
+
 #define DJ64_DEFINE_SWAPPABLE_CONTEXT(t, c) \
   static const struct t ctx_##t##_init = {}; \
   DJ64_DEFINE_SWAPPABLE_CONTEXT2(t, c, ctx_##t##_init,,)
diff --git a/src/libc/dos/io/dosio.c b/src/libc/dos/io/dosio.c
index 683ee81c..312eb4e3 100644
--- a/src/libc/dos/io/dosio.c
+++ b/src/libc/dos/io/dosio.c
@@ -11,13 +11,13 @@
 #include <libc/bss.h>
 #include <libc/djctx.h>
 
-static const char init_fh[] = {
-  O_TEXT,
-  O_TEXT,
-  O_TEXT,
-  O_BINARY,
-  O_BINARY
-};
+#define init_fh { \
+  O_TEXT, \
+  O_TEXT, \
+  O_TEXT, \
+  O_BINARY, \
+  O_BINARY, \
+}
 
 struct fh_state {
   char init_file_handle_modes[20];
@@ -32,6 +32,7 @@ char *__file_handle_modes;
 
 static const struct fh_state fhinit =
 {
+  .init_file_handle_modes = init_fh,
   .dosio_bss_count = -1,
   .count = 20,
 };
@@ -46,8 +47,12 @@ static void fhs_post(void)
 #define _RS(x) x = fhs->x
   _RS(__file_handle_modes);
 }
-DJ64_DEFINE_SWAPPABLE_CONTEXT2(fh_state, fhs, fhinit,
-    fhs_pre(), fhs_post());
+static void fhs_init(struct fh_state *st)
+{
+  st->__file_handle_modes = st->init_file_handle_modes;
+}
+DJ64_DEFINE_SWAPPABLE_CONTEXT3(fh_state, fhs, fhinit,
+    fhs_pre(), fhs_post(), fhs_init);
 
 #define init_file_handle_modes fhs->init_file_handle_modes
 #define dosio_bss_count fhs->dosio_bss_count
@@ -62,8 +67,6 @@ __file_handle_set(int fd, int mode)
   {
     dosio_bss_count = __bss_count;
     count = 20;
-    memcpy(init_file_handle_modes, init_fh, sizeof(init_fh));
-    __file_handle_modes = init_file_handle_modes;
   }
 
   /* Check for bogus values */